Question: Simplify the following expression: $x = \dfrac{1}{7k} + \dfrac{1}{2k}$
Answer: In order to add expressions, they must have a common denominator. The smallest common denominator is the least common multiple of $7k$ and $2k$ $\lcm(7k, 2k) = 14k$ $ x = \dfrac{2}{2} \cdot \dfrac{1}{7k} + \dfrac{7}{7} \cdot \dfrac{1}{2k} $ $x = \dfrac{2}{14k} + \dfrac{7}{14k}$ $x = \dfrac{2 +7}{14k}$ $x = \dfrac{9}{14k}$